Fabrication of Twin-Free Ultrathin NH2‑MIL-125(Ti) Membrane with c‑Preferred Orientation Using Transition-Metal Trichalcogenides as Titanium Source

In this study, layered TiS3, a kind of transition-metal trichalcogenide, was applied as the titanium source of NH2-MIL-125 during single-mode microwave-assisted secondary growth. Because of the appropriate Ti–S bond intensity and stability of TiS3, the solvothermal reaction could be conducted under milder reaction conditions, resulting in the formation of a twin-free, highly c-oriented ultrathin NH2-MIL-125­(Ti) membrane. This membrane exhibited exceptional H2 permeance while maintaining high H2 permselectivity.